JP2001248820A - Equipment and method for waste melting treatment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an equipment and method for waste melting treatment in which whether slag is solidified or not in the vicinity of a slag hole can be known. SOLUTION: A thermocouple 21, an oxygen concentration detector 22 and a differential pressure gauge 23 detect respectively temperature of a pipe line 11, oxygen concentration and flow differential pressure. In the detection, if it is found that the flow differential pressure is incinerated, the temperature in the pipe line 11 is at 85 deg.C or below, and the oxygen concentration is unchanged, the slag is judged to be solidified and deposited for some reason at the slag hole 62 by lowering of the temperature in a cyclone furnace 61. Accordingly ignition device of an oxygen burner 67 is actuated, and the burner 67 is burned to heat the slag hole 62, and the solidified and deposited slag is melted to flow down, and then it is removed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the combustion of decomposed solids obtained by partially burning combustible waste such as municipal solid waste to form fluidized slag which is dropped from the lower part of a melting furnace and recovered. The present invention relates to a waste melting treatment apparatus and a waste melting treatment method as described above.

[0002]

2. Description of the Related Art In recent years, environmental problems have attracted public attention, and regulations on various types of emissions such as exhaust gas, incineration fly ash and the like have become strict in municipal solid waste incinerators based on the same awareness. ing. In particular, reduction of highly toxic dioxins and detoxification and weight reduction by melting incineration ash have been required. On the other hand, as for the municipal waste, materials whose incineration heat value is large are increasing, and from the viewpoint of effective use of resources, it is required to generate electric power by the heat generated by the incineration and use the electric power. In the flow of such waste incineration technology, garbage is partially burned and thermally decomposed to generate decomposed solids containing flammable gas and combustibles, and the decomposed solids are incinerated at high temperatures, melted and melted. A refuse treatment system that forms slag and generates power using incineration heat has attracted attention.

FIG. 2 is a schematic diagram showing an outline of a conventional refuse incineration system. The outline of the waste incineration process will be described with reference to the figure. First, the waste is put into the screw feeder 1, and the screw feeder 1 supplies the waste to the fluidized bed gasifier 3. The temperature of the fluidized-bed gasification furnace 3 is raised in advance by the start-up burner 2 and maintained in a low oxygen atmosphere state. The size is designed so that the generation rate of char by pyrolysis and the generation rate of combustible gas are the same. The char and combustible gas discharged from the gasification furnace 3 are guided to a cyclone (centrifuge) 5 through a flue 4 to be separated into solid and gas.

The char discharged from the cyclone 5 is carried into a melting furnace 6. The calorific value of the loaded char is 150
Since it is as large as about 0 to 2000 cal / kg, only a small amount of fuel is used for starting the melting furnace 6 and it is 1300 to 1400 ° C.
It can be burned at high temperatures. The ash thus melted is discharged as slag, and the molten exhaust gas is discharged into the waste heat boiler 7.
And is subjected to heat exchange to generate steam. After the slag lower port was heated by the molten exhaust gas extracted from the lower part of the slag lower port, the exhaust gas was passed through a pipe 11 to an air preheater 9.
To preheat air.

On the other hand, the combustible gas separated and discharged from the cyclone 5 is guided to the combustion furnace 8 together with the high-temperature air sent from the air preheater 9 and burns there. A superheater 12 is disposed above the combustion furnace 8 and heat-exchanges the molten exhaust gas by superheating steam generated in the waste heat boiler 7. The superheated steam discharged from the superheater 12 is sent to a steam turbine 13, which rotates the steam turbine 13 to generate a power generator 1.
Turn 4 to generate electricity. The molten exhaust gas discharged from the waste heat boiler 7 is further sent to an air preheater 9 to recover heat by preheating the air. The air preheated by the air preheater 9 is also supplied to the gasification furnace 3 and the melting furnace 6 via a pipe 10 and the like, and is used as fluidized air and combustion air for a burner.

[0006] Further, the gas is discharged from the combustion furnace 8 and the processing pipe 1
The combustion exhaust gas led through 5 is supplied to a gas cooler 16 together with the molten exhaust gas heat recovered by the air preheater 9 and cooled, and then fly ash is removed by a bag filter (dust filter device) 17 to remove the fly ash. Chimney 1 by induction blower 18 as dust gas
It is forcibly exhausted from 9.

[0007]

As described above, the melting of the char in the melting furnace 6 is usually carried out at a high temperature of 1300 ° C. or more, but if the sealing air is excessively injected or the viewing window is rarely damaged. If it does, the temperature of the lower slag lowers rapidly and the lower slag may be blocked by the slag. Also, even if molten ash accumulates at the inlet of the gas extraction pipe and closes it, it is not possible to know the situation, and it is not possible to judge whether molten exhaust gas is being extracted from the gas extraction pipe. there were. An object of the present invention is to solve such a problem in the prior art and to provide a waste melting treatment apparatus and a waste melting treatment method capable of knowing whether or not slag has solidified in the vicinity of a slag lower opening. .

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to a waste melting treatment apparatus, comprising: an inlet for molten exhaust gas in a pipe for discharging molten exhaust gas branched from a lower end of a slag; Temperature detection means and oxygen concentration detection means for detecting the temperature and oxygen concentration of the molten exhaust gas in the vicinity, respectively,
A differential pressure detecting means for detecting a flow path differential pressure of the molten exhaust gas passing through the pipeline, for example, near the slag lower port, heating the slag lower port, the slag lower port portion A heating means for melting and flowing down the slag solidified and deposited on the surface may be provided.

Further, in the waste melting treatment method, the temperature and oxygen concentration of the molten exhaust gas in the vicinity of the inlet of the molten exhaust gas in the pipeline and the flow path differential pressure of the molten exhaust gas passing through the pipeline are respectively determined. The detection is performed to determine whether or not the slag in the lower part of the melting furnace has solidified.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a configuration diagram showing an outline of a melting furnace 6 and a measurement system according to an embodiment of the present invention. In the figure, reference numeral 20 denotes a measuring seat for measuring the temperature and oxygen concentration at the inlet of the conduit 11 of the gas extraction pipe, 21 denotes a thermocouple installed on the measuring seat 20, and 22 denotes a concentration installed on the measuring seat 20. An oxygen concentration detector 23 for detecting an oxygen concentration in the vicinity of the measurement seat 20 in the pipe 11 by a sensor, and a flow rate in the pipe 11 based on outputs from a plurality of pressure sensors (not shown) installed in the pipe 11 A differential pressure gauge for detecting a path differential pressure, 24 is an oxygen burner ignition controller for performing ignition control of an oxygen burner described later,
A recording device for recording the temperature in the chamber, 26 is an oxygen concentration detector 2
2 is a data processing device for processing oxygen concentration data from the pressure sensor 2, flow path differential pressure data from the differential pressure gauge 23, ignition control data from the oxygen burner ignition controller 24, and temperature data from the recording device 25.

Reference numeral 61 indicating the configuration of the melting furnace 6 denotes a cyclone furnace (primary combustion chamber) for heating and melting the char and residual ash supplied from the charging port, and 62 denotes a molten slag from the cyclone furnace 61. The slag lower opening, which serves as an outlet when flowing out, is the slag 63 described below.
A slag shielding net 64 for preventing entry into the next combustion chamber is a secondary combustion chamber for burning the molten exhaust gas, 65, 66.
Is an auxiliary burner for raising the temperature immediately downstream of the cyclone furnace 61 and the slag lower port 62 to the ignition temperature, and 67 is an oxygen burner for ejecting oxygen gas immediately downstream of the slag lower port 62. Although the configuration other than the melting furnace 6 is not shown, it has the same configuration as the conventional example.

Next, the operation of this embodiment will be described. In the cyclone furnace 61, the combustion temperature of the char and the residual ash, that is, 1300 ° -1
The char and residue ash that have been heated to 400 ° C., discharged from the cyclone 5 and injected into the cyclone furnace 61 from the inlet are partially burned there and self-heated,
Melts into a fluid slag. The slag flows down from the slag lower opening 62 of the cyclone furnace 61, falls into water, undergoes cold shrinkage crushing, and becomes granulated slag S.

On the other hand, the molten exhaust gas generated from the char and the residual ash melted in the cyclone furnace 61 passes through the slag lower opening 62 and the slag shielding net 63, and passes through the secondary combustion chamber 6
4, passes therethrough, and is discharged toward the waste heat boiler 7. Further, a part of the molten exhaust gas flowing out from the slag lower port 62 flows downward, passes through the pipe 11, and passes through the air preheater 9.
Sent to As described above, the thermocouple 21 and the concentration sensor are installed at the measurement seat 20 in the pipe 11 and
The temperature and oxygen concentration of the molten exhaust gas passing through are detected. The temperature and oxygen concentration of this molten exhaust gas are usually 850 ° to 10 °.
It is 5 to 7% at 00 ° C and 10% or less.

However, if the temperature in the cyclone furnace 61 decreases for some reason, such as excessive supply of char, the temperature of the slag lower opening 62 also decreases, and as a result, slag solidifies and deposits on the slag lower opening 62. Then, the flow rate of the molten exhaust gas discharged from the cyclone furnace 61 decreases, the temperature near the measurement seat 20 in the pipeline 11 decreases, and the flow rate differential pressure in the pipeline 11 increases. In these states, the thermocouple 21 and the differential pressure gauge 23 detect the temperature and the flow rate differential pressure in the pipeline 11, respectively, and the oxygen concentration detector 22 detects the oxygen concentration in the pipeline 11.

At this time, the flow rate differential pressure detected by the differential pressure gauge 23 increases, and the temperature in the pipe 11 detected by the thermocouple 21 becomes 85%.
° C or lower, the pipeline 1 detected by the oxygen concentration detector 22
Measure whether the oxygen concentration in 1 is higher than usual. If the oxygen concentration does not change, it can be determined that the slag has solidified and deposited at the lower portion 62 of the slag. Therefore, an ignition device (not shown) of the oxygen burner 67 is operated to burn the oxygen burner 67 and heat the lower portion 62 of the slag. Then, the slag solidified and deposited at the slag lower opening 62 is melted down and removed. When the temperature in the pipe 11 decreases and the oxygen concentration increases, the temperature in the pipe 11 decreases due to the melting furnace 6.
Since it is considered that air leaks into the inside, the operation of the melting furnace 6 is restarted after repairing the leaked portion.

As described above, the temperature, flow path differential pressure and oxygen concentration of the measuring seat 20 in the pipe line 11, that is, immediately downstream of the slag lower port 62, are measured by the thermocouple 21, the differential pressure gauge 23 and the oxygen concentration detector 22. To determine the state of the slag in the cyclone furnace 61, that is, whether the slag is solidified and deposited in the lower opening 62 of the slag, and whether there is leakage of air into the melting furnace 6. When the slag is solidified and deposited at the lower portion 62 of the slag, the slag solidified and deposited is burned by the oxygen burner 67 and the ignition control of the oxygen burner 67 is performed by the oxygen burner ignition controller 24. It can be stably melted and discharged from the slag lower opening 62.

[0017]

As described above, according to the present invention, the temperature and oxygen concentration of the molten exhaust gas and the flow path difference of the molten exhaust gas passing through the pipeline near the inlet of the conduit for discharging the molten exhaust gas. Since each pressure is detected, it is possible to easily determine whether or not the slag at the lower part of the melting furnace has solidified.For example, in the vicinity of the slag lower port, the slag lower port is heated to solidify and deposit slag. If slag solidified and deposited at the lower opening of the slag can be quickly removed by providing a heating means for melting and flowing down the slag, clogging of the lower slag of the slag due to solidification and accumulation of slag is prevented and waste melting is prevented. The suspension of the operation of the process can be avoided.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an outline of a melting furnace and a measurement system according to an embodiment of the present invention.

FIG. 2 is a schematic view showing an outline of a waste incineration system according to a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Screw feeder 3 Gasifier 5 Cyclone (centrifuge) 6 Melting furnace 7 Waste heat boiler 8 Combustion furnace 9 Air preheater 10, 11 Pipeline 16 Gas cooler 17 Bag filter (dust filter) 21 Thermocouple 22 Oxygen concentration detector 23 Differential pressure gauge 24 Oxygen burner ignition controller 26 Data processing device 61 Cyclone furnace (primary combustion chamber) 62 Slag lower port 63 Slag shielding net 64 Secondary combustion chamber 65, 66 Auxiliary burner 67 Oxygen burner S Water granulation Slug

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C04B 5/00 F23G 5/00 115Z F23G 5/00 ZAB 5/027 ZABZ 115 5/14 ZABD 5/027 ZAB F27D 19/00 D 5/14 ZAB B09B 3/00 ZAB F27D 19/00 303K (72) Inventor Naoki Fujiwara No. 3-36, Takara-cho, Kure-shi, Hiroshima Pref. 6-9, Takara-cho, Kure City, Hiroshima Prefecture Babcock Hitachi Kure Works F-term (reference) 3K061 AA11 AA23 AB02 AB03 AC01 AC03 BA05 BA06 CA01 CA07 DA14 DA19 DB11 DB20 FA05 FA10 FA21 FA27 3K062 AA23 AB02 AB03 AC01 AC19 BA02 CA02 CB08 DA01 DA12 DA22 DB12 4D004 AA46 BA03 CA24 CA29 CB34 DA01 DA02 DA03 DA06 DA07 DA10 4G012 JF03 4K056 AA19 BB01 CA20 DA02

Claims (3)

[Claims] 1. A char generated by pyrolysis of waste is introduced into a melting furnace and burned to form a fluid slag, and the slag is dropped from a lower slag opening at a lower portion of the melting furnace. While collecting, a part of the molten exhaust gas discharged from the lower port of the slag is branched and discharged from the lower port of the slag to the outside of the furnace through a pipe for discharging through a place where the slag is dropped. Waste melting equipment
A temperature detecting means and an oxygen concentration detecting means for detecting a temperature and an oxygen concentration of the molten exhaust gas near an inlet of the molten exhaust gas in the pipeline, respectively, and a differential detecting a flow path differential pressure of the molten exhaust gas passing through the pipeline. A waste melting treatment device comprising pressure detection means. 2. A heating means for heating the lower opening of the slag near the lower opening of the slag and melting and flowing down the slag solidified and deposited at the lower opening of the slag.
A waste melting treatment apparatus as described in the above. 3. Chars generated by pyrolysis of waste are introduced into a melting furnace and burnt to form fluid slag, and the slag is dropped from a lower slag opening at a lower portion of the melting furnace. At the same time as collecting, a part of the molten exhaust gas discharged from the lower port of the slag is branched, and discharged from the lower port of the slag through a discharge pipe through a place where the slag drops, so as to be discharged outside the furnace. In the waste melting treatment method, the temperature and the oxygen concentration of the molten exhaust gas near the inlet of the molten exhaust gas in the pipeline and the flow path differential pressure of the molten exhaust gas passing through the pipeline are detected, respectively. A waste melting treatment method comprising determining whether or not a lower slag has solidified.